USAAF Insignia

[Lugerlout]

Hi all, I picked up this small grouping at an auction yesterday, I am interested in collecting more of these insignia but could any one identify the small wings (single prop blade) 2nd row right ? I thought I had nailed it as a 'Technical Representative' insignia but have seen period photos of something similar being worn on the collars of USAAF uniforms, there are no markings on it so I hope it is'nt a 'sweetheart' type thing..............The others are..........

Top.....................................Marked 'Amico' 'Sterling' Aircrew Badge
Middle L to R........................Marked 'Amico' 'Sterling' Naval Aviator Badge also marked +1/20 10K, unmarked Button, unidentified.
Bottom L to R......................Marked Shold-R-Form 'Sterling' Captains Insignia, Unmared Major, 'Balfour' 'Sterling' Lt Col Insignia.

I think these USAAF/Navy/USMC aviator insignia are some of the most elegant designs, I know they are'nt uncommon or particularly valuable but I'm looking forward to having more in my collection.